Kitchen

[char1976]

Read something interesting today. PYREX and Pyrex are not made out of the same material. The Pyrex that is sold in the US is made with soda-lme glass and PYREX made in France is made of borosilicate glass. Supposedly that is why there was Pyrex breaking in the ovens because it was made of the soda-lime glass.

[GingerHead]

@char1976

 Oh wow, I had no idea. I'm going to look into this some more. Thanks for the head's up!

[Still Raining]

Lock n Lock has some glass bottomed items I have been looking at.

Would be interested to know what glass they use.  Wonder if PYREX/Pyrex is just a 'brand' or if it is really different?  

[Venezia]

I've known about the difference for years.

"Pyrex used to be made of the more heat-resistant borosilicate glass, which is more resistant to breakage when subjected to extreme shifts in temperature.  Pyrex eventually switched to tempered glass most likely because boron is toxic and expensive to dispose of. Although tempered glass can better withstand thermal shock than regular soda-lime glass can, it's not as resilient as borosilicate. This is what causes the shattering reaction people are talking about. Watch out for those casseroles."

[drizzellla]

@char1976 I had no idea. I saw Pyrex and thought it was all made with the same material. Never noticed the difference in the name on the label.

I checked my Pyrex items. And I have both types. I did not have a clue. But my Pyrex items say made in USA. And the PYREX 4 cup measuring cup says made in Corning, NY. 

[Venezia]

Either version of Pyrex should be fine, as long as you don't try to take it from a cold environment to hot immediately.  (Thermal shock is the issue.)

Also, if it's old, scratched, etc., best to replace it, if it's something you're going to put in the oven.  I have measuring cups that are years old.  No concern with using them at all.

[Icegoddess]

Personally, I wouldn't trust any Pyrex to now be made of bore silica.  If you can get ahold of your granny's Pyrex that you know is old, then that should be bore silica.  Lock n Lock is bore silica; they make a point of mentioning that in their presentations.  OXO also uses bore silica.  I just happened to notice it on a glass OXO piece I bought when BB&B was closing.

[deeva]

I have Pyrex that I got as wedding presents in the 70's, so I'm not worried about breakage.

[Melzie]

I read in an antique article somewhere that PYREX is the original and was also  manufactured in Corning, NY using borosilicate glass.  The NY operation was sold in 1998 and they had to change the name to Pyrex because the new owners used soda-lime materials in order to make it more affordable but made it less durable.  If you see an item with PYREX (all caps) it's the better product and older but Pyrex (initial cap only) it's not as durable and not a collectable.